High-Low Pressure Cycling

[Grub_Daddy]

I have a Pentair Sta-rite SLE-L that I think pumps around 11-13 gpm and the high and low pressure settings are at their factory settings of 50-30psi, respectively. After replacing a number rainbird sprinkler heads and spray nozzles with hunter pro-spray prs-40 + MP1000 rotators, I am having trouble with the pump cycling on and off between the high and low pressure switches. I am only using the manual start on the controller for a single zone at a time to test for now since I don't want to risk the pump starting in the middle of the night and then burning up from cycling constantly. Zone valves are Rain-bird DV100's but nothing is special about them. I believe its due to inadequate flow out of the new nozzles across the entire zone causing too much backpressure on the pump. Other zones are working fine but I now have got two zones I can't use. Is adding more sprinkler heads the only way to control this or is there something I can add to the zone supply line to regulate the pressure? I would prefer not to add sprinkler heads just for the sake of adding sprinkler heads.

 

[Reach4]

This sounds like a good application for a Cycle Stop Valve (CSV). That will maintain more consistent pressure while you are watering. It will stop the cycling.

But for the zones that are not putting out enough water, even while the water pressure is 40 psi, I would think you would need to put in different nozzles that will supply the water while the pressure is around 40. This may be a nozzle that puts out less water per minute, but throws farther. I am not experienced with irrigation.
https://www.lockewell.com/pdf/sta-rite/sl_series.pdf You have a 1-HP deep well jet pump. You may be able to adjust the pressure switch to a higher range. Turning the nut clockwise on the big spring typically raises the cut in and cut out pressures by about 10 PSI. There are different "jet packages" that trade pressure for volume.

 

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[WorthFlorida]

You're right on the two zone, the pump is putting out more water than the zones can dump water. Increase the sprinkler nozzles as before Or, If you have a Rainbird controller, you can tie two zone valves together on one controller zone. I've done it to my own irrigation. Hunter is not as robust and I've never try it with Orbit Controller. Each can drive two zone valves at the same time but I've found Hunter brand the copper lans on the mother board eventually burn out. That was years ago, they may have improved them by now. Another is if the zone valves are on a manifold or stacked next to one another, a few fittings you can tie the two zones together. Cut out one zone after the valve and tee it to the other zone.